1. Technical Field of the Invention
The present invention relates to a processing apparatus and a processing method for applying a designated treatment on a substrate, such as semiconductor wafer, by supplying a treatment liquid to the substrate.
2. Description of the Related Art
Generally, in the manufacturing field for semiconductor devices, there are various cleaning apparatuses which clean semiconductor wafers, which will be referred to “wafers” hereinafter, by designated cleaning liquids in order to remove various contamination, for example, particles, organic contaminants, metal impurities, etc. adhering to surfaces of the wafers. Among those apparatuses, there is a widely-used cleaning apparatus which can remove the particles etc. from a plurality of wafers by cleaning them on use of the cleaning liquids. In this apparatus, the wafers are accommodated in a cleaning bath into which the cleaning liquids are supplied.
As the conventional cleaning and drying apparatus of this kind, there is known a cleaning and drying apparatus which includes: one processing chamber provided, on one side thereof, with all opening for loading/unloading the wafers etc. and a door for closing the above opening; a rotor arranged in the chamber to rotate a carrier accommodating the wafers etc. slanted to the horizontal axis; liquid supply means for supplying liquid to the wafers etc.; and gas supply means for supplying gas to the wafers etc. (see U.S. Pat. No. 4,300,581) In connection, there is also known an apparatus which includes a detachable processing chamber for maintenance. (see U.S. Pat. No. 5,221,360) Further, this cleaning and drying apparatus has a structure where a motor and nozzles are attached to an attachment plate together with the above processing chamber. (see U.S. Pat. No. 5,022,419) There is also a cleaning and drying apparatus provided, in a drain/exhaust line in communication with a processing chamber, with gas-liquid separating means which separates the processing liquid into liquid and gas for discharge. (see U.S. Pat. No. 5,095,927) In connection, there is also known a structure where the gas-liquid separating means is equipped with a sensor. (see U.S. Pat. No. 5,154,199) In the cleaning and drying apparatus, upon closing the processing chamber in which a cassette accommodating the plural wafers etc. are carried in a rotor, it is carried out to rotate the rotor and the wafers while supplying cleaning liquid to the wafers etc. After completing the cleaning process, dry gas is supplied against the wafers etc. rotating together with the rotor, in the drying process. In the modification, there is an apparatus which directly loads the wafers etc. through its front face without using such a cassette. (see U.S. Pat. Nos. 5,678,320 and 5,784,797)
As another processing apparatus, a single wafer spinning apparatus is also provided with a plurality of processing chambers (cups) opening their upsides. (Japanese Examined Utility Model Publication kokoku No 4-34902)
In the above-mentioned cleaning and drying apparatuses, however, there are problems of not only hindrance but atmospheric disturbance in drying process due to the residual cleaning liquid used in the cleaning process since both cleaning process and sequent drying process are carried out in the single processing chamber. Of course, these problems arise in case of using one kind of cleaning liquid. Particularly in case of performing the cleaning process while using different kinds of processing liquids, for example, chemicals of resist stripper and polymer remover, solvent of these chemicals (e.g. IPA: isopropyl alcohol), processing liquid of rinsing liquid (e.g. pure water) etc.; the cleaning/drying process while using processing fluid, such as dry gas (inert gas (e.g. N2 gas) and fresh air); or the cleaning process while supplying an acid cleaning liquid (e.g. SPM), pure water, alkaline cleaning liquid (e.g APM in order, then such different kinds of chemicals would react with each other, causing the cross-contamination against the wafers etc.
In order to solve the above problem, it might be supposed to use different processing chambers in accordance with different kinds of processing liquids. However, such a measure would cause the processing efficiency to be deteriorated and additionally, the excessive requirement of footprint may cause the apparatus itself to be large-sized.
Note, although the above-mentioned single wafer spinning apparatus disclosed in Japanese Examined Utility Model Publication kokuku No. 4-34902 can somewhat prevent the processing liquids, such as chemicals of different kinds, from reacting with each other because of several processing chambers (cups), there is a problem of imperfectly preventing the wafers etc. from being contaminated since the cups are opened upward.